How to Encrypt & Decrypt Secret Message Using Invisible Ink

Secret writings are invisible writings that can be only seen after using any development technique which helps in revealing those hidden messages. Secret writings is being used since the middle of the 20th century for hidden messages. Secret writing was a source of communication for Prisoner’s. Invisible inks like biological fluids, vegetable juices, fruit juices can be used to write the hidden messages. These messages becomes visible when exposed to UV light and heat. In current research paper I had used 40 samples for both heat and UV. The secret message is written using Milk, Onion Juice, Urine and Soap water. These samples are subjected to heat and UV light every day till the last 20th day to decipher the secret message. The conclusion of the experiment is that the Heat method is the best method for deciphering the secret message.